As a result of a dramatic increase in litigation over the past ten years relating to issues of security, hotels have been forced to install specialized locking systems to insure security of guests and their property and to more accurately and securely control keys. Generally, the larger hotels have installed card locks or locks employing specialized keying systems, in order to restrict access to hotel rooms only to registered guests.
The major legal problem for a hotel is the loss of keys to rooms. Generally, a guest will fail to return a key upon checkout. In the old days, hotels would just make another duplicate of the original key, and periodically change the lock to each hotel room. Today, after many lawsuits, each and every time a guest does not return the key to his hotel room upon checkout, the combination of the lock is changed by all prudent hotel operators. Failure to insure that this standard is met may result in a hotel being found negligent.
There are several approaches to this problem. Winfield Locks, of Costa Mesa, Calif., manufactures a dual keyway cylinder, which allows for instant key change in the event of a lost key. These cylinders retrofit to existing lockset arrangements, and are quite popular. Another alternative is the use of magnetic stripe card locks, which can be reprogrammed instantly to lock out a guest card, and allow access to a newly verified card.
Yet another solution to this problem is the mechanical lock manufactured by TrioVing.TM., model 1040, 1050, or 1060, to which the present invention specifically relates. Each of these locks is a mechanical pin tumbler system, operating with the use of a plastic key card. The card is inserted into the lock to allow actuation of the bolt. The key is actually a plastic card with one or more holes punched in any one or more of 32 possible positions in a predetermined matrix. This design affords millions of individual key combination possibilities.
The modern pin tumbler locking principle has been known for almost one hundred and fifty years. It relies upon the theory of double detainer action, which requires that one or more sets of pins be lifted precisely to the level of what is known in the art as a "shear line." This is the point where the tumblers are able to split, and allow rotation or other movement of a cam, plug, movable locking member, or a similar device. When all tumblers are precisely set at "shear line," then the lock can be opened.
A unique variation of the pin tumbler design was patented in 1979, by Sornes, of Norway, assigned to TrioVing a.s. The lock described in this patent, U.S. Pat. No. 4,194,394, utilized 32 pin tumblers, located in a predetermined pattern which form a matrix of holes contained within a horizontal plane measuring approximately 2".times.1.75". When a plastic key card with the correct hole pattern is inserted into this lock, it will allow a horizontal movable locking member to be moved, to actuate an external bolt mechanism.
The design of these locks poses a problem for hotel staff and locksmiths in the case of a lockout problem. Unless an emergency bypass cylinder is operable, within the locking arrangement, there is no simple, rapid way to either open a lock, or produce a key for these locks. The lock can be extremely difficult to pick, using conventional methods. Thus, hotel staff, fire, police, emergency medical technicians, and locksmiths can find themselves in a position where they must destroy the lock, or the door supporting the lock, in order to gain entry to a hotel room. This can pose a threat to the safety of occupants of a hotel room, especially in the case of fire or a medical emergency, and particularly where the emergency bypass pin tumbler cylinder has not been installed, or is inoperable, due to mechanical failure or sabotage, or the emergency key is not readily available or has been lost. Generally, hotel room doors are constructed of heavy, solid wood, or metal and thus, the breaking and entering into a hotel room can be time consuming, and very costly. Such techniques are repugnant to professional locksmiths and hotel staff.
The VingCard.TM. system is extremely pick resistant to conventional methods of bypass. This means that it is difficult to insert a tool into the lock, and manipulate each tumbler, so as to cause that tumbler to break at shear line. The reader must understand, however, that there is a significant difference between picking the lock, and decoding the lock. This invention principally addresses the decoding of the lock.
Although many lock decoding devices have been patented, none have employed the concept of force sensing resistors, nor electronic means to decode the pressure of an individual pin within a pin tumbler lock. Many such decoders utilize feeler gauges, fine wires, or other similar devices in order to measure or determine the size and position of pin tumblers. All require a certain skill level to operate correctly, and will not provide a display of the data derived by use of the device.
Prior to the present invention, there has not been a decoding tool available which senses the pressure of pin tumblers, and specifically which would provide the required information from the TrioVing or similar locks regarding the placement and location of holes within the program code card, to allow rapid entry into the TrioVing lock, without inflicting heavy damage to the lock, door, door frame, and jamb.